Abstract

The photovoltaic effect (PVE) of a heterojunction composed of a (LCE) film and a Nb-doped crystal has been experimentally studied. A strong PVE was observed, and the maximum photovoltage was , when the LCE film was exposed to light with a wavelength of and a power of . The PVE remains significant up to , though it decreases gradually with the increase of wavelength. Oxygen release of the LCE film depresses the PVE considerably and modifies the rectifying property of the junction. A logarithmic variation of photovoltage with junction resistance was observed. The weakening of the ferromagnetic order of the LCE film due to the incorporation of oxygen vacancies may be the reason for the depression of the PVE.

This work has been supported by a direct grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. C001-2060228), and by the National Natural Science Foundation of China and the State Key Project for the Fundamental Research of China.